Islamic civilization between the 7th and the 15th centuries made great contributions to the development of science and medicine, and discoveries made during this time formed the basis for the emergence of the European Renaissance. Muslims view sleep as one of the great signs of Allāh, and a number of Muslim scholars studied and wrote on sleep and dreams. However, Muslim scholars' contributions to this topic have not been adequately represented in modern scholarship. Islamic scholars did far more than simply act as the preservers of the antiquity and Greek knowledge, but rather laid significant foundation, translation, interpretation, and transference of knowledge and experience, and have contributed original works in many fields of science and medicine including sleep. This brief article introduces some of the writings by Muslim scholars and philosophers about the importance of sleep, some sleep disorders, and dreams.